1. Field of the Invention
The invention relates to a fabric structure, and more particularly to a fabric structure having a heating function or a heat-retaining function.
2. Description of Related Art
Under the trend of globalization, the textile industry is facing severe competition, and textile manufacturers have to continue researching and developing new technology and diversified products to keep up with the worldwide competition. In order to satisfy diversified demands from consumers, a plurality of multi-functional fabric products are already available in the market, such as water-proof fabrics, warmth-retentive fabrics, or electrothermal fabrics.
A general electrothermal fabric has a structure including a surface layer, a heating layer, and a heat-insulating layer. A manufacturing process of the electrothermal fabric includes first weaving or knitting the surface layer, the heating layer, and the heat-insulating layer and assembling the surface layer, the heating layer, and the heat-insulating layer by performing a sewing process or an adhering process, such that the heating layer is sandwiched between the surface layer and the heat-insulating layer.
However, the manufacturing method of normal electrothermal fabrics requires one more sewing or adhering process to stack the three layers, and the sewing or adhering process is likely to allow air to exist between every two of the three layers, which results in air layers. The thermal conductivity of air is lower than the thermal conductivity of a normal surface layer, a normal heating layer, or a normal heat-insulating layer, and therefore the air layers reduce the thermal conductivity of the electrothermal fabrics. Moreover, when the surface layer, the heating layer and the heat-insulating layer are sewn together, the air layers distributed between every two of the three layers are likely to be distributed unevenly, such that uniformity of the thermal conductivity is affected, and that the temperature distribution of the electrothermal fabric is also uneven.